The feeding of a correction tape requires a separate feed device from that which feeds the printing ribbon on a typewriter or printer. This duplication of drive hardware is not only expensive, but provides additional potential for mechanism malfunction, thereby creating additional reliability problems.
In typewriters which utilize an oscillating cartridge system, the drives for feeding the ribbon and the correction tapes must, of necessity, either be mounted such that they move with the cartridges as the cartridge oscillates or alternatively must provide a flexible connection to the drive of the cartridge from the drive mechanism mounted on a fixed hardware mounting in the typewriter.
U.S. Pat. No. 4,302,118 to John O. Schaefer and assigned to International Business Machines Corporation discloses a ribbon and correction feed mechanism which is mounted on an oscillating ribbon feed plate which oscillates with the cartridge, thus functioning as if the cartridge and the ribbon mechanism were spacially fixed.
U.S. Pat. Nos. 3,863,749 and 3,871,507, both patents to Donald S. Perry et al, disclose a mechanism for drivingly engaging the ratchet teeth of a drive mechanism from the exterior of the cartridge while at the same time providing a lifting of oscillating mechanical input to the cartridge to effect ribbon lift. The device disclosed in these two patents is a multiple link lever chain driven by a cam to cause the feed of the ribbon. The patent does not disclose any technique for feeding of correction tape inasmuch as only one feed mechanism is disclosed.
As may be seen from the Perry et al patents, the oscillating cartridges complicate feed mechanisms since the feed mechanism must be able to feed and also accommodate the oscillatory motion of the cartridge. The same considerations are borne out by the feed mechanism disclosed by Schaefer in U.S. Pat. No. 4,302,118, referred to above.
It is an object of the invention to eliminate complex mechanical drives necessary to effect the incrementing of correction tape for an oscillating ribbon feed cartridge system.
It is a further object of the invention to simplify the correction tape feed in a ribbon feed system having both a ribbon and correction tape contained in oscillating ribbon cartridge and correction tape cartridge.